Reference is made to my previously filed patent application, Ser. No. 17,768, filed Mar. 9, 1970, and Ser. No. 173,861, filed Aug. 23, 1971, now U.S. Pat. No. 3,713,547, of which this application is a continuation in part, for further background of the invention. In one of my previous referred to apparatus, a pilot cable is utilized for moving pipe carriages along a single main cable way. The various pilot cables and other secondary cables are sometimes found to be cumbersome and often lead to complex mechanisms in order to properly control the longitudinal movement of the trough along the cable way.
In another of my previous apparatus, an endless cable is employed to which spaced carriages are positioned, with one of the carriages being slidable along the cable and another of the carriages being affixed to the cable, so that movement of the cable imparts motion into one of the carriages and hence, into a pipe which has been placed within both of the carriages.
In both of the previous apparatus referred to above, the pipe is subjected to considerable abuse while it is being transported between the spaced locations. Considerable experience and skill is required of an operator in order that he might operate the equipment without endangering workmen, as well as avoiding damage to the pipe which is being transported. Accordingly, it would be desirable to provide improvements in the art of transporting pipe along a cable way which overcomes many of the defects of the prior art. Further, it is desirable to provide improvements in the prior art pipe handling apparatus which avoids the possibility of a pipe being inadvertently dropped during its trip between the rack and the rig floor.